Still projector



A118 8, 1939- w. D. TEAsUE Er A1. 2,169,010

STILL PROJECTOR Filed Aug.- 14, 1937 Je 6256 F/' 545632 ATTORNEYS Patented Aug. 8, 1939 STILL PROJECTOR Walter D. Teague, New York, and DArcy A.

Young, Jr., Rochester, N. Y., signora to Eastman Kodak Company, litochester,I N. Y., a corporation o! New Jersey Application August 14, 1937, serai Nn. 159.144

4 claim. (cl. ais-24) The present invention relates to projectors, and more Particularly to projectors intended for use with 35 mm. or miniature transparency positives.

An object of the invention is the provision in such a projector, of a lamphousing which is detachable so that it may be readily removed to permit access to the lamp and to certain of the optical members.

Another object is the provision of a lamphouse which is movable as a unit with the optical members of the projector so as to always maintain the various optical members in the proper alignment.

Still another object of the invention is the provision in such a projector, of a mechanism which easily and quickly raises or lowers the optical axis of the projector, and which maintains the various parts in adjusted position.

A further object is the provision of a projector of the class described, which is simple in construction, positive in its action, easy to operate, and which aifords ready access to certain of the parts.

To these and other ends, the invention resides in certain improvements and combinations of parts all as will be hereinafter more fully described, the novel features being pointed out in the claims at the end of the specifications.

In the drawing:

Fig. 1 is a plan view of the projector with the lamphousing structure and the objective shown in broken lines;

Fig. 2 is a side elevation partly in section of the projector taken substantially on the line 2--2 of Fig. 1 with the lamphousing in position, showing the arrangement for detachably securing the lamphouse, and showing the mechanism for raising or lowering the optical axis of the projector;

Fig. 3 is a fragmentary vertical sectional view of the lower part of the projector, taken substantially on the line 3 3 of Fig. 2, showing the means for detachably securing the lamphouse in position, and the arrangment of the elevating mechanism for the lamp supporting member and the lamphousing; and

Fig. 4 is a fragmentary vertical sectional view taken substantially on the line I-l of Fig. 1, with the lamp supporting member in raised position, and showing the cam for raising and lowering the lamp supporting member and the lamphousing as a unit, the condenser lenses and their supporting frame have been omitted for the purpose of clarity.

Fig. 5 is a perspective view of a portion of the machine illustrated in Fig. 2, but on a larger scale than the latter, showing the arrangement for locking the lamphousing to the pivoted support.

Similar reference numerals throughout the several views indicate the same parts.

The invention comprises, in its broadest aspect, a base on which a supporting member is pivotally mounted about a horizontal axis so that a portion thereof may be raised or lowered relative to the base for changing the optical axis of the projector. This supporting member carries the condenser lenses as well as a light source in the form of an incandescent lamp. A lamp housing is mounted on and movable as a unit with this supportingmember, and carries the objective lens system of the projector. The lamp housing is releasably secured to the supporting member so that it may be easily detached therefrom to permit ready access to the lamp as Well as the condenser lenses. A slotted cam mounted on the base cooperates with a cam follower or pin carried by the supporting member so that the latter, together with the lamphousing, may be raised or lowered relative to the base to adjust the vertical position of the optical axis of the projector.

-Referring now to the drawing, there is shown a projector constructed in accordance with the preferred embodiment of the invention. This invention comprises, in general, a base Il formed of any suitable material, preferably Bakelite, having a at top I2 and depending side and end walls I3 so as to provide a hollow dish-like member, as shown in Figs. 2 and 3. The corners of the base are formed with short depending members or feet I4 which may be provided with suitable cushions or pads I5, preferably of felt or other `similar material. The base II is preferably of U-shape having spaced arms or members IB and I 1 to which a supporting member I8, hereinafter more fully described, is pivotally mounted. Each of the arms I6 and I1 has secured thereto, by means of screws I9, a metal angle-iron one leg 2| of which extends under the arm Ii or I1 while the other leg 22 thereof extends up along the inner surface of the arm, as clearly shown in Fig. 3.

The supporting member I8 is also preferably formed of Bakelite to provide a at top 24 depending side walls 25 and depending front and back walls 26 and 21 respectively. The top 24 preferably extends substantially across the space between the arms I6 and I1, as shown in Fig. 1, while the side walls 25 extend downwardly therebetween, as shown in Fig. 3. The top 24 has mounted thereon a lamp socket 28 in which an incandescent lamp 29 is mounted in the usual and well-known manner. The condensing lenses 30 and the reflector 3| are all carried in a single unitary frame member 82 mounted on an angle `iron= 33 which in turn is suitably secured to the under side of the top 24, as shown in Fig. 2. A heat resisting member I4 is preferably interposed between certain of the condenser lenses, as shown in Fig. 2.

The opposite side walls 2l. of the suDPOrt Il have laterally projecting bearing pins 4l which extend outwardly from the walls 2l and are Journalled in registering openings formed in the vertical` legs 22 of the angle irons, thus affording bearings in which the pins 48 are 1006.121? mounted. These bearing pins are l rear of the support Il, as shown in Flgal and 2, and provide pivot points for mounting the support I8 on. the base Il so thatthe support may Vbe raised or lowered, by mechanism to be later described, to move the optical axisfof the proector so that the image area of the transparency may be centered on a projection screen. as is well known.

A thin circular cam 42, having a spiral slot 42 formed therein, is mounted on the inner-end of a shaft 44 which is journalled in the arm I5 of the base Il, and extends through an openingI 45 formed in the adjacent side wail 251 oi'fthel member I8. The cam 42 lies adJacent the inner face of this side wall, and projects upwardlyl into. a slot 46 formed in the top 24 of the member Il,

as shown in Fig. 3. A metal pin or cam follower i 41 is imbedded in the member Il and extends across the slot 46 and through the slot 43 of the cam 42 so that upon rotation of the` cam the pin will ride on the edges of the cam slot to raise or lower the support i8, as is apparent from inspection of Figs. 2 and 4. The camis rotated by means of a hand controlled knob 4I which is secured to the outer end of the shaft. and projects upwardly into operating position through an aperture 49 formed in the base ii, as clearly illustrated in Figs. l and 3.

The top of the support I8 has formed integral therewith a pair of spaced bearings Il positioned at the rear upper edge o'f the support, as s'hown in Figs. 1 and 2. These bearings carry a small rod or pintle 52, which engages cooperating membar 55 both of which are Asecured to the member I8 by means of screws 55, as best shown in Pigs. 1 and 3. The screws 56 extend through slots 55:,

in the lower bar 55 so that the latter may be moved or slid laterally relative to the top stationary bar 54, as is apparent from an inspection of Fig. 5. The lower sliding bar II is formed with a pair of rearwardly extending spaced open end slots 51, only one of which is shown in'Pig. 5, which are arranged to receive cooperating lugs on the lamphousing to lock the latter to the support, in a manner to be presently described. The ends 58 of the sliding bar 5I are preferably bent upwardly, as shown in Fig. 3, to form gripping portions to slide the bar.

The lamphouse 53 is of the shape best shown in Fig. 2, and is also preferably formed of Bakelite to provide a top 58, sides 5|, a front 52 and a back 53. The top 8|! is provided with louvres 64 through which the heat from the lamp 25 .may escape, as is well known. 'I'he front OZ-fhas se.

cured thereto a tube 55, preferably Bakelite..

positioned adiaceat'tne k lamp and lenses.

assist in radiatina `any heat transmitted by the lamp 2l.. However, in order to reduce the radiation of thelamp. the latter is preferably enclosed in a U-shaped case or shield arranged on three sidesv of the lamp, the side toward the condensing lens, of course, being open so that light rays may pass through the optical members of the projector. This supporting case comprises U-shaped metal wall members 1l and 1I which are separated by a lining of suitable heat insulating material 12. such. for example, as glass wool, all of which is clearly shown in Fig. 2. 'f This insulating shield is preferably secured to and movable as a unit with the lamphousing and extends into a registering opening 18 formed in the top l in the lamphousing. Top louvres 14 are also provided in the top of the insulated casing so as to provide an exit for the heat generated by the lamp 28. A black metal cap 'Il is preferably positioned over the top of the lamp 28 to reduce the light rays which may pass through the louvres 14, as is welll known. The opposite sides 5l of the lamphousing are formed with aligned slots 18 in which a transparency holding slide. not shown, is arranged to be moved back ariddorth through the optical field of the projector. so as to bring the various transparencies into position in the optical field. as is well known to those in the art.

'I'he top 8l o'f the lamphousing also preferably carries a depending flexible member in the form of a U-shaped spring, the legs 'I1 of which arel Fig. 2, and presses lightly thereon to resiliently retainthese members in position in the frame member 82.

Referring now to Fig. 2, the lower edge of the back "fof the lamphousing has secured thereto,

in any suitable manner, metal lugs each of .which is formed with a rearwardly extending open end slot 8i adapted to receive the pintle 52 to detachably secure the lamphousing to the support IQ. The lower edge of each of the sides 6I of Ythelamphousing is also provided with a similar metal lug l2 having a forwardly extending open end slot 83 which is in registry with the slot 51 formed in the sliding bar 55 when the latter is in the position shown in Fig. 5. When, however, the sliding bar 55 is moved to its dotted position shown in Fig. 3, the slot 51 is moved out of registry with the slot Il of the lug 82,' and the latter ist' locked in position to secure the lamphousing to the support Il. When the slot 83 is thus closed. the screws 56 engage the ends of the slots 5I to limit the lateral movement of the bar II so 'as to space the finger or gripping portion 58 from the slide wall il of the lamphousing, as is apparent from an inspection of Fig. 5. The bars 54 and 5I thus cooperate with the pintle 52 to detachably secure the lamphousing on the support Il. When the housing is thus secured, the entire projector may be picked up by means of the lens tube 65, so that the latter also forms a. handle by which the projector may be carried or moved.

When the lamp 29 is to be replaced, or the condenser lenses are to be cleaned, the lamp- ',housing may be readily detached from the supporting means to lprovide complete access to the Io remove the housing, the sliding bar 5l is iirst slid from the dotted position CTI to the full line position shown in Fig. 3, thus bringing the slot 5l thereof into registry with the slot 83 of the lug 82. The housing 53 is then tipped slightly upward about the pintle 52, and is then moved forwardly to slide the pintle 52 out of the slots 8l of the lugs 8l. The housing is now free, and may be removed by lifting it vertically. Free access is now providedboth to the lamp and to the condenser lenses. When, however, the housing is to be replaced, it is ilrst moved downwardly over the lamp and lens assembly until the slots 8i are in alignment with the pintle 52, the front end of the housing being slightly elevated. The housing is then slid rearwardly to bring the pintle 52 into slots 8| of the lugs 80. The front end of the housing is then slightly depressed to move the slots 83 ofthe lugs 82 into registry with the slots 51 of the sliding bar 55. The latter is then slid to the right, as viewed in Fig. 3, to lock the housing to its support I8, as above described.

Referring again to Fig. 2, it is apparent that when the cam 42 is rotated in clockwise direction, the pin or camfollower 41 will engage the edges of the cam slots 43 to elevatel the front of the 4support I8 and the lamphousing 53 to raise the optical axis of the projector. When, however, the cam 42 is rotated in the opposite direction, the support and lamphouse are moved downwardly to lower the optical axis of the projector. In this raising and lowering operation, the support I8 and the lamphousing 53 move as a unit on the pivot or bearing pins 40 so that the optical members of the projectors arealways maintained in proper alignment. It is apparent that due to the weight of the support I8 and the lamphousing 53, more force must be applied to the knob 48 in the elevating operation than in thelowering operation. It is desirable, however, in. a machine of this type that the force necessary to both raise and lower the support be substantially equal, or nearly so.

To this end, the present invention provides an arrangement which assists the cam 42 in the elevating operation, but which tends to act against the cam in the lowering movement. This arrangement comprises, in the present embodiment, a U-shaped counter-balance spring 90 the ends 9I of which are secured by screws 92 to the under side of the legs 2I of the angle irons as clearly shown in Figs. 2 and 3. An intermediate portion 93 of the spring 9U engages the lower edge 94 of the iront Wall 26 of the support I8, as shown in Figs. 2 and 4 and tends to lift the support I8 and the lamphousing 53 as a unit, as is apparent from inspection of the drawing. Thus when the cam 42 is rotated to elevate the support in the lamphousing, the spring 90 cooperates with the cam to assist in this elevating movement; but, when the cam is rotated in the opposite direction to lower the members, the spring tends to hold these members in elevated position. By means of this v arrangement, the spring 99 eifectively balances out the weight oi' the support I8 and the housing 53 so that the force for raising and lowering these members is substantially equal, the advantage of which is obvious.

It is apparent from the above description, that the present invention provides a projector construction in which the lamphousing is securely locked in position, yet may be readily and easily released and removed to afford free access to the lamp and the condenser lens assembly. It is also apparent that the optical axis of the projector may be quickly and easily raised or lowered so as to center the image oi' the projected transparencies on the viewing screen. In this raising and lowering operation, all` of the optical members are moved as a unit thus positively assuring that these members will always be maintained in proper alignment.

While one embodiment of the invention has been disclosed, it is to be understood that the inventive idea may be carried out in a number of ways. This application is, therefore, not to be limited to the precise details described, but is in .tended to cover all variations and modifications thereof falling within the spirit of the invention or the scope ot the appended claims.

We claim: l

1. In an apparatus for projecting transparencies, a base, a support pivotally secured adjacent one end thereof to said base, a lamp carried by said support. a lamp housing mounted on and movable with said support, a slotted lug secured to and depending from said lamphousing, a slotted bar slidably mounted on said support, said bar being movable into one position to bring the slot therein into registry with the slot in said lug to permit removal of said lamphousing from said support, said bar being slidable to another position to move the slot therein out of registry with the slot in said lug to lock said lamphousing on said support, and means engaging said support adjacent the other end thereof to adjust said support and said housing relative to said base.

2. In an apparatus for projecting transparencies, a base, a support adjustably mounted on said base, a lamp carried by said support, a condenser lens mounted on said support and movable therewith, a lamp housing detachably secured to said support, a U-shaped spring secured to and movable with said lamphouse and formed with a portion arranged to engage said lens independently of said support but cooperating therewith to maintain said lens in position, means for adjusting said support and said housing relative to said base, and a counterbalance member operatively connecting portions of said base and said support and cooperating with said means to facilitate adjustment of said support.

3. In an apparatus for projecting transparencies, a base, a supporting member pivotally secured adjacent one end thereof to said base, a

ilamp carried by said support, a frame member mounted on said support, a condensing lens and a lamp reflector supported in said frame member; a housing member mounted on said support and movable as a unit therewith, a spring on said housing adapted to engage said lens to yieldably retain the latter in position in said frame member, lugs on said housing member, said lugs being formed with open end slots, a pintle on said support adjacent said one end and arranged to be positioned in the slots of certain of said lugs, a'

slidable member comprising a at metal strip slidably mounted on the opposite end of said support, said slidable member being movable in one direction to close the slots in others of said lugs and to cooperate with said pintle to lock said housing on said support, said slidable member being also movable in the opposite direction to open said last mentioned slots to enable said housing to be detached from said support, a cam on said base engaging said support adjacent said other end to adjust said support and said housing members relative to said base, and an operating knob for said cam mounted on said base.

4. In an apparatus for projecting transparencies, a base, a supporting member pivotally secured adjacent one end thereof to said base, a lamp and optical members carried by said support, a housing member mounted on said support and movable as a unit therewith, a spring secured to and movable with said housing member and arranged to engage certain of said optical members to yieldably retain the latter in position on said support and in alignment with the optical axis of said lamp. lugs on said housing member, said lugs being formed with open end slots, a pintle on said support adjacent said one end and arranged to be positioned in the slots o! certain of said-lugs, a slidable member comprising a flat metal strip slidably mounted on the opposite end o! said support adapted to close the slots in others oi' said lugs and cooperating with said pintle for detachably securing said housing member to said support, a cam on said base engaging said support adjacent said other end to adjust said support and said housing members relative to said base, a counterweight spring secured to said base and having an intermediate portion thereof engaging said support adjacent said other end, said spring cooperating with said cam in adjusting said support and a hand-control knob for said cam mounted on said base.

WALTER D. TEAGUE. DARCY A. YOUNG, Ja. 

